Re-treading method and apparatus

ABSTRACT

A re-treading method and an apparatus therefor, which are capable of winding a tread material on a base tire automatically and efficiently to realize an adequate joint condition of the leading and trailing edges of the tread material, are configured to take a photograph of a zone of the tread material including its cut position to compare the picture with a stored tread pattern image to detect a deviation amount between them, then moves the tread material or the cut position relative to each other by the deviation amount, next cut the tread material at the cut position after the relative movement, wind the tread material on a base tire, and unite the leading and trailing edges of the tread material. Alternatively, the re-treading method and the apparatus can detect a deviation amount of the position distant by a required tread length from the leading edge of the tread material from a predetermined pattern position near that position planned to be cut, cut the tread material at the at the predetermined position, wind the cut-out tread material on the outer circumference of the base tire while adjusting the length of the tread material by applying thereto a substantially uniform tensile or compressive force, and unite the leading and trailing edges of the tread material wound on the base tire.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to retreading method and machinery forfabricating a recapped tire by cutting a vulcanized tread material,vulcanized in form of a continuous belt, such that leading and trailingedges to be bonded meet in tread pattern, and then winding the treadstrip on a base tire.

[0003] 2. Description of the Related Art

[0004] In a pre-curing method (cold recapping method), which winds on abase tire a vulcanized tread (pre-cured tread) strip having a patternformed on its surface, then bonds its leading and trailing edges, andvulcanizes the tire in a vulcanization chamber, the vulcanized treadstrip is previously vulcanized and molded in a length corresponding tothe length of one to three tires, and this tread material is cut andwound on a prepared base tire, followed by bonding its leading andtrailing edges.

[0005] Typically used for this bonding is a technique that wraps thecircumferential surface of a base tire with a tread rubber materialapproximately up to 340 degrees, loosely putting the remainder of thetread rubber material on the base tire to find a position meeting theleading edge, where the remainder part of the tread rubber materialshould be cut, then marks that position and cut it there with a cutter,and bonds the resultant trailing edge of the tread rubber material inabutment with the leading edge.

[0006] This method, however, could not provide a high productivitybecause it relies on operator's visual detection of the position of thetread rubber to be cut before bonding the leading and trailing edges andon operator's manual task of cutting it with a cutter.

[0007] Furthermore, although this method cuts out a strip from a treadmaterial to meet with the length of the outer circumference of a basetire, base tires have various circumferential lengths depending ondifferences in growth amount of the outer diameter, differences in outerdiameter among different patterns of tire manufacturers, and so on.

[0008] Thus the cut position is not constant relative to the surfacepattern, and divided pattern blocks come out with various sizes.

[0009] For example, assume that a tread material 01 having a treadpattern as shown in FIG. 10 is to be cut at the cut position C-C′.

[0010] When a particular pattern block B is remarked, one divisionalpattern block b at one side of the cut position C-C′ has a larger volumewhereas the other divisional pattern block b′ has an extremely smallvolume.

[0011] If a divisional pattern block with such an extremely small volumeremains on a recap after being molded, the recap is liable to sufferlocal wearing, during use, at the portion of the divisional patternblock b′ bonded with a small length of bonding as shown in FIG. 11showing an example of joint of the leading and trailing edge.

[0012] In some cases, a groove and a block portion may come to butt atthe joint of the leading and trailing edges of the tread rubbermaterial, which will make a defective joint and will lead to localseparation of the joint.

[0013] Furthermore, unless divisional pattern blocks of the leading edgeand the trailing edge do not meet well, there occur size differences inblocks at the joint of the leading and trailing edges, and this maycause local wearing, or, if a pattern groove or a thin filleted blockend abuts with the cut surface of a pattern block, separation of thejoint will occur due to the defective bonding, and the outer aspect ofthe pattern will be damaged.

[0014] To cope with these problems, there is a method of ensuringpattern matching at the joint between the leading and trailing edges bypreparing a tread rubber material having a leading edge and a trailingedge cut along a line having the same pattern as the cut line of theleading edge and distant from the leading edge by a length nearest tothe required length, and putting the tread rubber material on the basetire while expanding or contracting it to adjust its length with thecircumferential length of the base tire.

[0015] This conventional method, however, burdens operators with varioustasks upon cutting the tread rubber material at a desired patternposition. That is, an operator must stop the machine to confirm the cutposition by lightly pressing a cutter on the tread rubber material, orestimate the cut position from the anvil position of the cutter; if thecut position is not a proper position, the operator must move the treadrubber material to a proper position by manually operating a conveyor orother transport machine; and he or she actually cuts it after a gainconfirming the cut position.

[0016] As reviewed above, since the but position is visually confirmedby an operator and manually adjusted in position, high accuracy of thecutting position cannot be expected even at the cost of the requiredtime and labor.

[0017] While winding the tread rubber material on the base tire, whenthe operator winds the last part of the tread rubber material afterfinishing the winding of a larger half of the tread rubber, the operatormust expand or contract the last part of the tread rubber material toadjust the length such that the trailing edge comes into exact abutmentwith the leading edge.

[0018] Therefore, the cutting task is inefficient, and the finishingquality of the winding job is largely affected by the skill of theoperator.

[0019] Further, since the tension or compression is locally concentratedto the trailing end portion of the tread rubber material, the treadrubber material cannot be wound on the base tire in a uniform condition.

SUMMARY OF THE INVENTION

[0020] It is therefore an object of the invention to overcome thoseproblems and provide a re-treading method and an apparatus therefor,which employ pattern matching free from local wearing or separation atthe joint, and uses an imaging means to cut a tread materialautomatically, efficiently and precisely so as to ensure patternmatching.

[0021] A further object of the invention is to provide a re-treadingmethod and an apparatus therefor, which employ pattern matching freefrom local wearing or separation at the joint, and expand or contractthe tread material uniformly, automatically and efficiently to adjustits length so as to ensure pattern matching when winding the treadmaterial, thereby to realize an adequate bonding condition of theleading and trailing edges.

[0022] According to the invention recited in claim 1, there is provideda re-treading method comprising: transporting a predetermined amount ofa vulcanized tread material vulcanized and molded in form a continuousbelt from a cut position; photographing an image of a tread pattern in azone of said tread material including said cut position; comparing saidphotographed tread pattern image with a tread pattern image storedbeforehand to detect a deviation amount between them; moving said treadmaterial or said cut position relative to each other by said deviationamount; cutting said tread material at the cut position after therelative movement; and winding said tread material cut out and joiningleading and trailing edges thereof.

[0023] The pattern block to be cut is roughly determined by transportingthe vulcanized tread material from the cut position and thereby roughlydetermining the trailing end cut position of the tread material whichwill make a length near the length required for wrapping the base tire.

[0024] Then by photographing the tread pattern at the cut position,comparing it with the tread pattern image stored beforehand, and cuttingthe tread material at that cutting position if both images coincide, thetread material can be cut at the predetermined position on the pattern.If a deviation is found by comparison with the stored tread patternimage, by detecting the deviation amount and relatively moving the treadmaterial or the cut position by the deviation amount, the tread materialcan be cut at the predetermined position on the pattern.

[0025] Therefore, it is ensured that the tread material is always cut atthe predetermined position on the pattern near the position at therequired tread length, and the leading and trailing edges of the treadmaterial wound on the base tire match well in pattern at the joint.

[0026] In this manner, cutting of the tread material for patternmatching can be executed automatically, efficiently and precisely.

[0027] Since the edges match in pattern, the joint is unlikely to sufferlocal wearing or separation, and its outer aspect is good as well.

[0028] According to the invention recited in claim 2, there is furtherprovided a re-treading method comprising: transporting a predeterminedamount of a vulcanized tread material vulcanized and molded in form acontinuous belt from a cut position; photographing an image of a treadpattern in a zone of said tread material including said cut position;judging whether said deviation amount is in an allowable range; movingsaid tread member or said cut position relatively to each other by saiddeviation amount upon judging that said deviation amount is in theallowable range, or not moving same judging that said deviation is inthe allowable range; cutting said tread material at said cut positionrelatively moved or not moved; and winding said tread material cut outand joining leading and trailing edges thereof.

[0029] The pattern block to be cut is roughly determined by transportingthe vulcanized tread material from the cut position and thereby roughlydetermining the trailing end cut position of the tread material whichwill make a length near the length required for wrapping the base tire.

[0030] Then by photographing the tread pattern at the cut position,comparing it with the tread pattern image stored beforehand, and cuttingthe tread material at that cutting position if a deviation amount iswithin an allowable range, the tread material can be cut at thepredetermined position on the pattern. If the deviation is found to beout of the allowable range, by relatively moving the tread material orthe cut position by the deviation amount, the tread material can be cutat the predetermined position on the pattern.

[0031] Therefore, it is ensured that the tread material is always cut atthe predetermined position on the pattern near the position at therequired tread length, and the leading and trailing edges of the treadmaterial wound on the base tire match well in pattern at the joint.

[0032] In this manner, cutting of the tread material for patternmatching can be executed automatically, efficiently and precisely. Sincethe edges match in pattern, the joint is unlikely to suffer localwearing or separation, and its outer aspect is good as well.

[0033] The invention recited in claim 3 is based on the re-treadingmethod recited in claim 1 or 2, and characterized in said tread patternimage stored beforehand includes a planned cut line, and said plannedcut line is determined to ensure that all of divisional pattern blocksdivided by cutting respective blocks of said tread pattern image have avolume not smaller than a predetermined value.

[0034] Since the planned cut line is set at a position ensuring that alldivisional pattern blocks have a volume not smaller than a predeterminedvalue, no divisional pattern block having an unacceptably small volumeis produced when the corresponding actual tread material is cut at thecut position, and various disadvantages including local wearing orseparation at the joint of the leading and trailing edges can beprevented.

[0035] The invention recited in claim 4 is based on the re-treadingmethod recited in one of claims 1 through 3, and characterized in thatsaid cut position is moved relative to said tread material by saiddeviation amount.

[0036] This is configured to move the cut position by the deviationamount relative to the tread material held stationary, and to cut thetrailing edge of the tread material at the moved cut position.

[0037] The invention recited in claim 5 is based on the re-treadingmethod recited in one of claims 1 through 3, and characterized in thatsaid tread material is moved relative to said cut position by saiddeviation amount.

[0038] This is configured to move the tread material by the deviationamount and cut the trailing edge of the tread material at a fixed cutposition, and can therefore move the tread material just by thedeviation amount by using a tread material feeding machine.

[0039] According to the invention recited in claim 6, there is provideda re-treading method comprising: detecting a deviation amount between aposition at a required tread length from the leading edge of avulcanized tread material vulcanized and molded in form of a continuousbelt and a predetermined pattern position near said position planned tobe cut; cutting said tread material at said predetermined patternposition; winding said tread material cut out on the outer circumferenceof a base tire while adjusting the length thereof to remove saiddeviation amount by applying thereto a substantially uniform tensile orcompressive force; and joining leading and trailing edges of said treadmaterial wound on said base tire.

[0040] Since the tread material is cut always at the predeterminedpattern position, the leading and trailing edges of the tread materialwound on the base tire meet well in pattern at the joint. Therefore, thejoint is unlikely to suffer local wearing or separation, and its outerappearance exhibits a good quality.

[0041] Since the deviation amount between the position at the distancecorresponding to the required tread length necessary for winding thetread material on the base tire from the leading edge of the vulcanizedtread material and the predetermined pattern position near that positionplanned to be cut is detected, it is possible to wind the tread materialon the outer circumference of the base tire while adjusting its lengthby applying a substantially uniform tensile or compressive force to thetread material toward removing the deviation, and it is thereforepossible to automatically and efficiently adjust the tension orcompression of the tread material uniformly over the entire lengththereof upon winding it and to realize an adequate joint condition ofthe leading and trailing edges.

[0042] The invention recited in claim 7 is based on the re-treadingmethod recited in claim 6 and characterized in further comprising:photographing a tread pattern in a portion distant by the required treadlength from the leading edge of said vulcanized tread materialvulcanized and molded in form of a continuous belt; and comparing thephotographed tread pattern image with a tread pattern image storedbeforehand to detect said deviation amount.

[0043] Since the deviation amount is detected by photographing the treadpattern in a zone at the position distant by the required tread lengthfrom the leading edge of the tread material and comparing it with thestored tread pattern image, the deviation amount can be detectedprecisely, efficiently and automatically.

[0044] The invention recited in claim 8 is a method of feeding the treadmaterial onto the base tire under rotation and winding it in there-treading method recited in claim 6 or 7, and it is characterized infurther comprising: calculating the peripheral speed of said base tirealong the maximum outer diameter thereof during rotation of said basetire at a predetermined angular velocity; calculating a tread feedingspeed which can apply a tensile or compressive force to said treadmaterial toward removing said deviation amount from the peripheral speedof said base tire, said required tread length and said deviation amount;and winding said tread member fed at the calculated tread feeding speed.

[0045] By detecting the deviation amount beforehand, it is possible tocalculate, beforehand, the tread feeding speed relative to theperipheral speed of the base tire to which a tensile or compressiveforce is applied toward removing the deviation amount, and it istherefore possible to automatically and efficiently adjust the tensionor compression of the tread material uniformly over the entire lengththereof upon winding it and to realize an adequate joint condition ofthe leading and trailing edges.

[0046] The invention recited in claim 9 is a method of feeding the treadmaterial onto the base tire under rotation and winding it in there-treading method recited in claim 6 or 7, and it is characterized infurther comprising: feeding said tread material at a constant treadfeeding speed; calculating a peripheral speed of said base tire whichcan apply a tensile or compressive force to said tread material towardremoving said deviation amount from said tread feeding speed, length ofsaid tread member and said deviation amount; and winding said treadmaterial onto said base tire rotated at the calculated peripheral speed.

[0047] By detecting the deviation amount beforehand, it is possible tocalculate, beforehand, the peripheral speed of the base tire relative tothe constant tread feeding speed, which ensures application of a tensileor compressive force toward removing the deviation amount, and it istherefore possible to automatically and efficiently adjust the tensionor compression of the tread material uniformly over the entire lengththereof upon winding it and to realize an adequate joint condition ofthe leading and trailing edges.

[0048] The invention recited in claim 10 is based on the re-treadingmethod recited in claim 6, and it is characterized in that said treadmaterial is cut into a tread length which ensures that the ratio of saiddeviation amount relative to the tread length of said tread material cutout falls in the range from −4% to 2%.

[0049] If the ratio of the deviation amount relative to the tread lengthis out of the range from −4% to 2%, the expanding or contracting ratioof the vulcanized tread material is excessively large, and adisadvantage may occur in the tread material.

[0050] The invention recited in claim 11 is based on the re-treadingmethod recited in claim 6, and it is characterized in that said treadmaterial is cut into a tread length which ensures that the ratio of saiddeviation amount relative to the tread length of said tread material cutout falls in the range from −2% to 0.5%.

[0051] The ratio of the deviation relative to the tread lengthpreferably falls in the range from −2% to 0.5% for the vulcanized treadmaterial undergoing expansion or contraction.

[0052] According to the invention recited in claim 12, there is provideda re-treading apparatus comprising: a transport means for transporting avulcanized tread material vulcanized and molded in form of a continuousbelt; a cutting means for cutting said tread material at a cut position;a photographing means for photographing a tread pattern of said treadmaterial; a storage means for storing a predetermined tread patternimage beforehand; an adjusting means for adjusting the cut position bymoving said tread material and said cut position relative to each other;and a control means including said storage means to control saidtransport means, said cutting means, said photographing means and saidadjusting means, said control means controlling said transport means totransport the vulcanized tread material vulcanized and molded in form ofa continuous belt by a predetermined amount from the cut position;controlling said photographing means to photograph a tread pattern in azone of said tread material including said cut position; comparing thephotographed tread pattern image with the tread pattern image storedbeforehand to detect a deviation amount therebetween; controlling saidadjusting means to relatively move said vulcanized tread material andsaid cut position by said deviation amount; and controlling said cuttingmeans to cut said tread material at the cut position after the relativemovement, thereby to obtain a tread material to be wound on a base tire.

[0053] By transporting a predetermined length of the tread member fromits cut position with the transport means, the cut position of thetrailing edge of the tread member is roughly determined at a positionnear the required length necessary for winding it on the base tire isroughly determined, and the tread pattern in a zone including the cutposition is photographed by the photographing means. Thus, by comparingit with the stored tread pattern, and if it coincides, the treadmaterial is cut at that cut position, thereby to cut it at thepredetermined position on the pattern. If the comparison results infinding a deviation from the stored tread pattern image, the deviationamount is detected, and the tread material or the cut position isrelatively moved by the deviation amount by the adjusting means. Thusthe tread material can be cut at the predetermined position on thepattern by the cutting means.

[0054] Therefore, it is ensured that the tread material is always cut atthe predetermined position of the pattern near the required length andthat the leading and trailing edges of the tread material wound on thebase tire meet well in pattern at the joint.

[0055] In this manner, cutting of the tread material for patternmatching can be executed automatically, efficiently and precisely.

[0056] Since the pattern matching is ensured, the joint is unlikely tosuffer local wearing or separation, and its outer appearing is good aswell.

[0057] According to the invention recited in claim 13, there is provideda re-treading apparatus comprising: a transport means for transporting avulcanized tread material vulcanized and molded in form of a continuousbelt; a cutting means for cutting said tread material at a cut position;a photographing means for photographing a tread pattern of said treadmaterial; a storage means for storing a predetermined tread patternimage beforehand; an adjusting means for adjusting the cut position bymoving said tread material and said cut position relative to each other;and a control means including said storage means to control saidtransport means, said cutting means, said photographing means and saidadjusting means, said control means controlling said transport means totransport the vulcanized tread material vulcanized and molded in form ofa continuous belt by a predetermined amount from the cut position;controlling said photographing means to photograph a tread pattern in azone of said tread material including said cut position; comparing thephotographed tread pattern image with the tread pattern image storedbeforehand to detect a deviation amount therebetween; judging whetherthe deviation amount falls within an allowable range or not; controllingsaid adjusting means when judging said deviation amount is not in theallowable range to relatively move said tread material or said cutposition by said deviation amount; not moving said tread material orsaid cut position when judging said deviation amount is in the allowablerange; and controlling said cutting means to cut said tread material atthe cut position relatively moved or not moved, thereby to obtain atread material to be wound on a base tire.

[0058] By transporting a predetermined length of the vulcanized treadmaterial from its cut position, the cut position of the trailing edge ofthe tread material near the required length necessary for winding it onthe base tire is roughly determined, and the tread pattern in a zoneincluding the cut position is photographed by the photographing means.Thus, by comparing it with the stored tread pattern, and if a deviationamount is in the allowable range, the tread material is cut at that cutposition, thereby to cut it at the predetermined position on thepattern. If the comparison results in finding a deviation from thestored tread pattern image beyond the allowable range, the treadmaterial or the cut position is relatively moved by the deviationamount. Thus the tread material can be cut at the predetermined positionon the pattern by the cutting means.

[0059] Therefore, it is ensured that the tread material is always cut atthe predetermined position of the pattern near the required length andthat the leading and trailing edges of the tread material wound on thebase tire meet well in pattern at the joint.

[0060] In this manner, cutting of the tread material for patternmatching can be executed automatically, efficiently and precisely. Sincethe pattern matching is ensured, the joint is unlikely to suffer localwearing or separation, and its outer appearing is good as well.

[0061] According to the invention recited in claim 14, there is provideda re-treading apparatus comprising: a deviation amount detecting meansfor detecting a deviation amount between a position at a required treadlength from the leading edge of a vulcanized tread material vulcanizedand molded in form of a continuous belt and a predetermined patternposition near said position planned to be cut; a cutting means forcutting said vulcanized tread material; a base tire support meansrotatably supporting a base tire; a tread material feeding means forfeeding the vulcanized tread material cut at said predetermined patternposition by said cutting means onto said base tire; and a control meansfor controlling the peripheral speed of said base tire or the treadfeeding speed by said tread material feeding means to wind said treadmaterial on the outer circumference of said base tire while adjustingthe length of said tread material by applying a substantially uniformtensile or compressive force to said tread material cut out towardremoving said deviation amount.

[0062] Since the tread material is always cut at the predeterminedpattern position, the leading and trailing edges of the tread materialwound on the base tire meet well in pattern at the joint. Therefore, thejoint is unlikely to suffer local wearing or separation, and its outerappearance exhibits a good quality as well.

[0063] Additionally, since it detects the deviation amount between theposition distant by the required tread length necessary for winding thetread material on the base tire from the leading edge of the vulcanizedtread material and the predetermined pattern position near that positionplanned to be cut, it is possible to wind the tread material on theouter circumference of the base tire while adjusting its length byapplying a substantially uniform tensile or compressive force to thetread material by controlling the peripheral speed of the base tire orthe tread feeding speed toward removing the deviation, and it istherefore possible to automatically and efficiently adjust the tensionor compression of the tread material uniformly over the entire lengththereof upon winding it and to realize an adequate joint condition ofthe leading and trailing edges.

[0064] The invention recited in claim 15 is based on the re-treadingapparatus recited in claim 14, and it is characterized in that saiddeviation amount detecting means includes a photographing means forphotographing a tread pattern in a zone at a required tread length fromthe leading edge of said vulcanized tread material vulcanized and moldedin form of a continuous belt, and detects said deviation amount bycomparing the tread pattern image photographed by said photographingmeans with a tread pattern image stored beforehand.

[0065] Since it detects the deviation amount by photographing the treadpattern in a zone at the required tread length from the leading edge ofthe tread material by using the photographing means and comparing itwith the stored tread pattern image, the deviation can be detectedprecisely, efficiently and automatically.

[0066] The invention recited in claim 16 is based on the re-treadingapparatus recited in claim 14 or 15, and it is characterized in thatsaid control means correlatively controls the peripheral speed of saidbase tire and said tread feeding speed from the length of said treadmaterial and said deviation amount toward removing said deviation amountfrom said tread material, and winds said vulcanized tread material ontothe outer circumference of said tire while applying a substantiallyuniform tensile or compressive force to said vulcanized tread material.

[0067] By detecting the deviation amount beforehand, it is possible tocalculate, beforehand, the peripheral speed of the base tire the treadfeeding speed are correlatively controlled to ensure application of atensile or compressive force toward removing the deviation amount, andit is therefore possible to automatically and efficiently adjust thetension or compression of the tread material uniformly over the entirelength thereof upon winding it and to realize an adequate jointcondition of the leading and trailing edges.

BRIEF DESCRIPTION OF THE DRAWINGS

[0068]FIG. 1 is a schematic diagram showing procedural steps ofmanufacturing recaps in a precure recapping method;

[0069]FIG. 2 is a side elevational view of the entirety including cutterand a bonding machine;

[0070]FIG. 3 is a flowchart that shows control procedures in the cuttingprocess;

[0071]FIG. 4 is a diagram that shows aspects under different cuttingsteps;

[0072]FIG. 5 is a diagram that shows a simplified tread pattern image;

[0073]FIG. 6 is a diagram that shows another simplified tread patternimage;

[0074]FIG. 7 is a diagram that shows changes of the tread feeding speedand the peripheral speed of the base tire upon application of a tensionto the pre-cure tread;

[0075]FIG. 8 is a side elevational view of the entirety including thecutter and the bonding machine during winding of the pre-cure tread ontoa base tire;

[0076]FIG. 9 is a diagram that shows a pattern-matched joint conditionof the leading and trailing edges of the pre-cure tread;

[0077]FIG. 10 is a diagram that shows a tread pattern of a precure treadand a conventional cut position thereof; and

[0078]FIG. 11 is a diagram that shows a pattern-mismatched jointcondition of the leading and trailing edges of a pre-cure tread.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0079] A preferred embodiment of the present invention will now bedescribed with reference to FIGS. 1 to 9. A method and an apparatusaccording to the invention for cutting a vulcanized tread material areapplied to a pre-cure recapping system for recaps.

[0080] The precure recapping is a recapping method in which after a usedtire has its tread shaved off to recreate a base tire, tread vulcanizedand molded with pattern grooved therein is attached to the base tire andthen vulcanized in a vulcanization chamber to recap the used tire.Procedural steps of creating a recap by means of the precure recappingare outlined in FIG. 1.

[0081] In an inspection process P1, used tire has its surface, holesmade by nails, and gashes examined to determine if it is recappable bymeans of the retreading, and if not, that tire is excluded.

[0082] The recappable tire subsequently undergoes buffing in the nextprocess P2, and it has an outer circumferential surface of the treadshaved off to be finish as a base tire.

[0083] The base tire is fixed by partial polishing and/or void fillingbetween buffing and winding procedures.

[0084] In a process P3 carried out in parallel, tread rubber material issubjected to the precure vulcanizing and molding to createpattern-embossed tread.

[0085] The precure tread vulcanized and molded with pattern embossedthereon is shaped in continent belt, and it is cut into strips of adesired length during a cutting procedure in the next process P4.

[0086] In a winding process P5, the precure tread is wound around thebase tire.

[0087] In advance of the winding of the precure tread, after coating theouter circumferential surface of the base tire with cement, cushionsheet is affixed, or alternatively, cushioning may be applied directlyto the base tire by a push bench.

[0088] The tire at this point is rotatably supported, and the precuretread is sent from a feeder and wound around the outer circumferentialsurface of the tire.

[0089] In a succeeding process P6, leading and trailing edges of theprecure tread wound on the base tire are joined via cushion rubber andunited together by a stapler.

[0090] The base tire muffled by the precure tread is enclosed in asuck-shaped sheet or an envelope, and beads are attached to rims(process P7) so as to air-tightly seal the envelope.

[0091] After being wound by the precure tread and enclosed in theenvelope, several such base tires are put together in the vulcanizationchamber and vulcanized (process P8).

[0092] After the vulcanization, the rims and envelop are removed tofinish the tires as recaps (process P9).

[0093] The present invention relates to the cutting process P4 among theaforementioned procedures.

[0094]FIG. 2 shows a cutter 20 and a tread bonding machine 50 forexecuting the cutting process.

[0095] The cutter 20 is disposed in a middle point of a roller conveyor10 driven by a servo motor 11, and has a slide mount 23 slidablysupported on a stationary chassis 21 via an LM guide 22, a nut member 25which is in engagement with a ball screw 24 rotatably supported by thechassis 21 to extend in the front and back directions and integrallyattached to the slide support 23, and the ball screw 24 rotated by theservo motor 26 via a timing belt 26 a.

[0096] When the ball screw 24 rotates with a driving force from theservo motor 26, the nut member 25 in engagement with the ball screw 24can slide in the front and back directions integrally with the slidesupport 23.

[0097] An anvil 27 spans on the top surface of the slide support 23, anda cross member 29 is supported to bridge posts 28, 28 that stand atright and left ends.

[0098] A support rod 30 hangs down from the bottom surface of the crossmember 29 for sliding movements in the right and left directions, and arotary cutter 31 is provided at its lower end to be rotated by a motor.

[0099] A support rod 30 can slide in the right and left direction with aforce from an air cylinder 32.

[0100] Therefore, when the air cylinder 32 drives the rotary cutter 31rotated by the motor in the right and left directions, the precure treadTpc on the anvil 27 can be cut.

[0101] At the front and back positions of the moving stroke of therotary cutter 31, material weights 33, 34 are provided.

[0102] An L-shaped arm 37 is suspended from a horizontal support member35 backwardly projecting from the center of the cross member 29, interms of the right and left directions, to be moved by an air cylinder36 in the front and back directions, and a camera 38 for imageprocessing is attached to the distal end of the arm 37.

[0103] Since the arm 37 moves in the front and back directions with adriving force from the air cylinder, the camera 38 at the distal end ofthe arm moves forward from its withdrawal position shown in FIG. 2 andcan advance to a predetermined position above a central position wherethe rotary cutter 31 moves, where the camera 38 can take a picture ofthe pattern in a zone including the cut position on the precure treadTpc located below.

[0104] The main body of the cutting machine, including the rotary cutter31, camera 38, material weights 33, 34, their driving mechanisms, andothers, is entirely held on the slide support 23 and can be movedentirely by the servo motor 26 to change the position to be cut by therotary cutter 31 in the front and back directions.

[0105] In front of the roller conveyor 10, an elongated belt conveyor 40is provided to extend diagonally upward toward a base tire T₃ rotatablysupported, and the bet conveyor 40 rotates with a force from a servomotor 41.

[0106] Photoelectric switches Ph1 and Ph2 are located sequentially inthe feeding direction at predetermined positions downstream and abovethe belt conveyor 40.

[0107] The photoelectric switch Ph1 is located at a predetermineddistance D1 from the cut position by the rotary cutter 31, and thephotoelectric switch Ph2 is located at a predetermined distance D2 fromthe photoelectric switch Ph1 in the downstream direction such that thephotoelectric switches Ph1 and Ph2 can successively detect the leadingedge of the precure tread Tpc transported by the belt conveyor 40.

[0108] At a more downstream position near one end of the belt conveyor40, a plurality of centering rollers are aligned in the right end liftsides to guide opposite sides of the transported precure tread Tpc andthereby feed it while positioning it in the center.

[0109] The leading edge of the belt conveyor 40 is located in closerelation with and diagonally above the base tire T₃ rotated by the servomotor (not shown), and the tread bonding machine 50 lie on the leadingedge of the belt conveyor 40 to above the base tire T₃.

[0110] The tread bonding machine 50 includes a first roller 51 locatedabove the leading edge of the belt conveyor 40 to urge the precure treadTpc against the roller 42 at the leading end of the belt conveyor 40 andfeed it while preventing it from slippage, a second roller 52 locatedabove the base tire T₃ to urge the precure tread Tpc against the basetire T₃ and bond it while preventing it from slippage, and a thirdroller 53 located between the first roller 51 and the second roller 52to prevent the precure tread Tpc from deformation.

[0111] All of the first, second and third rollers 51, 52, 53 are freerollers.

[0112] Upon bonding, the tread bonding machine 50 controls thedifference between the feeding speed of the belt conveyor 40 and theperipheral speed of the base tire T₃ while winding the precure tread Tpcsent from the belt conveyor 40 onto the base tire T₃, thereby to apply atensile force or a contractive force to adjust the length. In thisprocess, the first, second and third rollers 51, 52, 53 help the treadbonding machine 50 to smoothly perform the bonding task.

[0113] The cutting process (process P4) and the winding process (processP5) are executed by the cutting machine 20 and the tread bonding machine50 explained above.

[0114] As to the cutting process, control procedures are shown in theflowchart of FIG. 3, and respective aspects of the precure tread Tpc andthe cutting machine 20 are shown in FIG. 4.

[0115] The cutting process is now explained along with the flowchart,occasionally referring to FIG. 4.

[0116] In step S1, a required length Lt of tread necessary for windingit on the base tire T₃ is calculated by multiplying the outercircumferential length Lc of the base tire T₃ by a correctioncoefficient γ.

[0117] Since the outer circumferential length Lc of the base tire T₃ istargeted when buffing the tire to be recapped, the same target value maybe used. By using classifying base tires and using a uniformcircumferential length Lc for each class, it is possible to managevarious kinds of tires with a small number of control values, simplifythe control while maintaining a high accuracy and thereby improve theefficiency of the cutting process.

[0118] It is also possible to newly measure the outer circumferentiallength Lc by, for example, rolling the roller on outer circumferentialsurface of the base tire T₃ and detecting the number of rotations of theroller with a rotation sensor.

[0119] When the outer circumferential length Lc of the base tire T₃ thusdetermined is multiplied by the correction coefficient γ found bycalculation, the required length of tread Lt (=Lc≅γ) of the precuretread Tpc, which can be just wound on the outer circumferential surfaceof the base tire T₃ can be obtained.

[0120] The correction coefficient γ is the value taking cushion rubberinterposed on the peripheral surface of the base tire T₃ intoconsideration.

[0121] The belt-like elongated pattern-embossed precure tread Tpcvulcanized and molded in the PC molding process P3 already explained istransported by the roller conveyor 10, passing through the cuttingmachine 20, and the leading portion of the precure tread Tpc re-rides onthe belt conveyor 40 and is transported at the same speed. At first,however, the precure tread Tpc is fed at a high speed (step S2).

[0122] The photoelectric switch Ph1 is located at a distance(predetermined distance D1 (for example, 2850 mm)) corresponding toapproximately 95% of the required length of tread Lt (for example, 3000mm) from the cut position by the rotary cutter 31 of the cutting machine20, and when the leading edge of the precure tread Tpc sent at a highspeed is detected by the photoelectric switch Ph1 (step S3), the speedis changed to a low speed (step S4).

[0123]FIG. 2 shows the configuration at the time when the leading edgeof the precure tread Tpc under a high speed is detected by thephotoelectric switch Ph1 and the speed is changed to a low speed.

[0124] When the photoelectric switch Ph2 located downstream thephotoelectric switch Ph1 by the distance D2 (for example, 100 mm)detects the leading edge of the precure tread Tpc (step S5), the servomotors 41, 11 are changed to step-feeding modes for transporting thetread by counting pulses (step S6).

[0125]FIG. 4(1) shows the configuration at the time when the leadingedge of the precure tread Tpc under a low speed is detected by thephotoelectric switch Ph2 and the feeding mode is changed to a stepfeeding mode.

[0126] The step feeding mode ensures that a predetermined length of theprecure tread Tpc is accurately fed for the trailing edge to be cut.

[0127] Assuming that the required length of tread Lt is 3000 mm,D1=2850, and D2=100 mm, the high speed feeding mode is employed toshorten the work time until the tread runs the distance 2850 mmcorresponding to a large part of its length from the cut position of thecutting machine 20, whereas the low speed feeding mode is employed forthe next distance 100 mm such that the photoelectric switch Ph2 canaccurately detect the leading edge of the precure tread Tpc.

[0128] When the precure tread Tpc runs the distance 2950 mm from the cutposition of the cutting machine 20, the remainder 50 mm is converted tothe number of pulses of the servo motors 41, 11, and the servo motors41, 11 are driven in the pulse driving mode to precisely feed the 50 mmlength of the tread step by step while counting the pulses.

[0129] In general, the length for step-by-step feeding is calculatedfrom L5−(D1+D2).

[0130] In this manner, by stopping the precure tread Tpc at the pointwhere the required length thereof Lt is accurately runs from the cuttingposition of the cutting machine 20 and cutting the trailing edge of theprecure tread Tpc at that cutting position with the rotary cutter 31,the precure tread Tpc having the required tread length Lt can be cut outprecisely.

[0131] However, in case the trailing edge of the precure tread Tpc iscut in the aforementioned manner, it is not ensured that tread patternsare cut at a predetermined position, and therefore, it cannot beexpected that patterns match when the leading and trailing edges arejoined.

[0132] Taking it into consideration, at the point where the precuretread Tpc is transported in the step feeding mode by the required treadlength Lt in step S6, the image processing camera 38 provided in thecutting machine 20 is brought ahead to the predetermined position, andthe zone including the cutting position on the surface of the precuretread Tpc is photographed (step S7).

[0133]FIG. 4(2) shows the configuration at that point of time.

[0134]FIGS. 5 and 6 show tread pattern images Pt simplified intosolid-line rectangles.

[0135] On the other hand, an image processing control device stores atread pattern image near the cut position, and a planned cut line S-S′is preset in the stored tread pattern image Pm.

[0136]FIGS. 5 and 6 each show the tread pattern image Pm and the plannedcut line S-S′ overlapping on a screen of the photographed tread patternimage Pt.

[0137] The rectangular block shown by the broken line is the storedtread pattern image Pm, and the planned cut line S-S′ is preset at apredetermined position of the tread pattern image Pm.

[0138] The planned cut line S-S′ simultaneously shown on the treadpattern image Pt taken by the camera 38 corresponds to the cut line C-C′at the corresponding position of the actual precure tread Tpc, and thecutting machine 20 is configured to actually cut the precure tread Tpcwith the rotary cutter 31 running along the cut line C-C′.

[0139] That is, the planned cut line S-S′ corresponding to thephotographed tread pattern image Pt in FIG. 5 and FIG. 6 results inshowing the position of the corresponding tread pattern to be actuallycut.

[0140] The planned cut line S-S′ is determined to ensure that alldivisional pattern blocks divided by cutting respective blocks of thetread pattern images have volumes not smaller than a predeterminedvalue.

[0141] Therefore, when a tread material is cut at a corresponding actualcut position, none of divisional pattern blocks has an unacceptablysmall volume, and disadvantages including local wearing or separationalong the joint after joining the leading and trailing edges can beprevented.

[0142] After the tread pattern in the zone including the cut position ofthe precure tread Tpc is photographed in step S7, the photographed treadpattern image Pt and the stored tread pattern image Pm are stacked adshown in FIGS. 5 and 6 to compare them (step S8).

[0143] If there is any difference between them, by computing the area ofa part of the photographed tread pattern image Pt out of the storedtread patter image Pm (the hatched portion in FIG. 5 of FIG. 6), thedeviation amount d can be detected (step S9).

[0144] The deviation amount d is a positive value when the photographedtread pattern image Pt is offset in the upstream side of the storedtread pattern image Pm, and it is a negative value when the deviation isin the opposite downstream side.

[0145] It is next judged whether the deviation amount d is within apredetermined allowable range (−α-+α) or not (step S10), and if it is inthe allowable range as shown in FIG. 5, the flow directly jumps to thestep S15 to withdraw the camera 38. If the deviation amount d is out ofthe allowable range, the flow goes to the step S11 to judge whether thedeviation amount d is positive or negative.

[0146] If the deviation amount d is a positive value out of theallowable range (d>α), then the flow goes to the step S12, where theservomotor 26 is activated to move the main body of the cutting machine20 to the downstream side by the deviation amount d to again take atread pattern image with the camera 38 in step S14, then compare bothtread pattern images and confirm that the new deviation amount is in theallowable range.

[0147]FIG. 4(3) shows the configuration where the main body of thecutting machine has been moved forward by the deviation amount d.

[0148] At that time, the planned cut line S-S′ moves relatively to thephotographed tread pattern image Pt to lie at the position shown by thetwo-dot chain line as shown in FIG. 6.

[0149] If the deviation amount is a negative value out of the allowablerange (d<−α), then the flow goes from the step S11 to the step 13, andafter moving the main body of the cutting machine 20 to the upstreamside by the deviation *d*, the flow goes to the step S14.

[0150] Although the foregoing embodiment is configured to move the mainbody of the cutting machine 20, it is also possible to hold itstationary and instead move the precure tread Tpc by the deviationamount −d. In this case, the movement direction is opposite from thatexplained above.

[0151] In step S15 after confirmation in step S14, the camera 38withdraws from the predetermined position, the material weights 33, 34move down (step S16), and press and fix front and back positions of thecut position of the precure tread Tpc. After that, in step S17, therotary cutter 31 runs and cuts the trailing edge of the precure treadTpc.

[0152]FIG. 4(4) shows the configuration immediately after the cutting.

[0153] Since the trailing edge of the precure tread Tpc is cut in theabove-explained process, the cut position of the precure tread Tpcalways reliably comes to the predetermined position on the tread patternnear the required length of tread Lt.

[0154] Therefore, when the cut-out precure tread Tpc is wound on thebase tire T₃ and its leading and trailing edges are joined, theseleading and trailing edges always reliably cut at predeterminedpositions on a pattern match in pattern at the joint as shown in FIG. 9.Therefore, local wearing or separation along the joint are unlikely tooccur, and the outer aspect is also good.

[0155] However, although the actual cut-out length of the precure treadTpc is near the required length of tread Lt, it is still different fromthe required tread length Lt by the movement distance (deviation amountd) of the main body of the cutting machine 20.

[0156] Taking it into consideration, when the precure tread Tpc is woundon the base tire T₃, a tensile or compressive force is applied theretoto adjust its length.

[0157] That is, the actual length of the precure tread Tpc is Lt−dwhereas the difference from the required tread length Lt is d, and theratio (expanding or contracting ratio) δ of the difference d relative tothe actual tread length Lt−d is d/(Lt−d).

[0158] When the expanding or contracting ratio δ is a positive value, itindicates the value of tension, and if it is a negative value, itindicates the value of contraction.

[0159] If the expanding or contracting ratio δ is excessively large, adefect will occur in the precure tread Tpc itself. Therefore, theprecure tread has to be cut to have a tread length Lt−d in the rangefrom −4% to 2% (from 4% of tension to 2% of contraction), and preferablyin the range from −2% to 0.5%.

[0160] Taking it into consideration, there is a method of correcting thedeviation amount d to minimize the movement of the main body of thecutting machine 20 in steps S12 and S13 within the allowable range(−α-α).

[0161] For the purpose of adjusting the length by applying a tensile orcompressive force when the precure tread Tpc is wound on the base tireT₃, a difference is made between the tread feeding speed V1 of theprecure tread Tpc by the belt conveyor 40 and the peripheral speed V2 ofthe maximum outer diameter of the base tire T₃.

[0162] In case of changing the tread feeding speed V1 while fixing theperipheral speed V2 of the base tire T₃, the tread feeding speed V1 isreset to a value calclated from V1=V2≅(1−δ), and changes in speed uponapplication of a tension of δ>0 is shown in FIG. 7.

[0163] In FIG. 7, the broken line shows the peripheral speed V2 of thebase tire T₃, and the solid line of lower speeds is the tread feedingspeed V1.

[0164] Referring to FIG. 8, since the leading portion of the precuretread Tpc sticking onto the base tire T₃ is wound at the peripheralspeed V2 whereas the trailing portion sent at the tread feeding speed V1is fed at a lower speed, the precure tread Tpc is wound on the base tireT₃ while being expanded under a tensile force.

[0165] The precure tread Tpc cut to the tread length Lt−d is transportedat the tread feeding speed V1 by the belt conveyor 40, and after guidedand centered from opposite sides by the centering rollers 45 neat theleading edge, it is sent out onto the base tire T₃ while sandwichedtogether with the conveyor belt between the roller 42 and the firstroller 51 for the purpose of preventing slippage.

[0166] The precure tread Tpc sent out sticks from its leading edge onthe peripheral surface of the base tire T₃ rotating at the peripheralspeed of V2, and it is progressively wound while pressed against thebase tire T₃ by the second roller 52 for preventing slippage.

[0167] When the tread feeding speed V1 is lower than the peripheralspeed V2 of the base tire T₃, a tensile force is applied to the precuretread Tpc between the first roller 51 and the second roller 52 to expandthe precure tread Tpc while the base tire T₃ is wound.

[0168] If the tread feeding speed V1 is higher than the peripheral speedV2 of the base tire T₃, a compressive force is applied to the precuretread Tpc between the first roller 51 and the second roller 52, and theprecure tread Tpc is compressed while it is wound the base tire T₃.

[0169] When a compressive force is applied to the precure tread Tpc, theprecure tread Tpc is prevented from deforming between the first rollerand the second roller 52 under a pressure from the third roller 53.

[0170] Since the precure tread Tpc is progressively wound on the basetire T₃ while a tensile or compressive force is applied to the precuretread Tpc by adjusting the tread feeding speed V1 in the above-explainedmanner, the precure tread Tpc is precure tread Tpc adjusted to therequired tread length Lt by the tensile or compressive force during onerevolution of the base tire T₃ to ensure that the leading and trailingedges meet substantially precisely.

[0171] Then the leading and trailing edges of the precure tread Tpcwound on the base tire T₃ are joined together by a stapler, or the like,via cushioning rubber interposed therebetween.

[0172]FIG. 9 shows the joint of the leading and trailing edges of theprecure tread Tpc with a straight line. As shown in FIG. 9, both edgesmatch in tread pattern at the joint, and therefore, the joint isunlikely to suffer local wearing or separation, and its outer appearanceis good as well.

[0173] To apply a tensile or compressive force to the precure tread Tpc,the foregoing embodiment changes the tread feeding speed V1 while fixingthe peripheral speed V2 of the base tire T₃. However, it is alsopossible, in contrast, to fix the tread feeding speed V1 while changingthe peripheral speed V2 of the base tire T₃.

[0174] In this case, the peripheral speed V2 of the tire T₃ iscalculated from V2=V1/(1−δ).

[0175] As described above, by comparing the tread pattern image taken bythe camera 38 with the stored tread pattern image and thereby detectingthe deviation amount d beforehand, it is possible to actually cut thetread material automatically, efficiently and precisely such that theleading and trailing edges of the precure tread Tpc wound on the basetire T₃ match in pattern with each other, and to wind the tread materialproperly while automatically expanding it. Therefore, recaps having anexcellent lifetime can be manufactured with high accuracy andefficiency.

What is claimed is:
 1. A re-treading method comprising: transporting apredetermined amount of a vulcanized tread material vulcanized andmolded in form a continuous belt from a cut position; photographing animage of a tread pattern in a zone of said tread material including saidcut position; comparing said photographed tread pattern image with atread pattern image stored beforehand to detect a deviation amountbetween them; moving said tread material or said cut position relativeto each other by said deviation amount; cutting said tread material atthe cut position after the relative movement; and winding said treadmaterial cut out and joining leading and trailing edges thereof.
 2. Are-treading method comprising: transporting a predetermined amount of avulcanized tread material vulcanized and molded in form a continuousbelt from a cut position; photographing an image of a tread pattern in azone of said tread material including said cut position; judging whethersaid deviation amount is in an allowable range; moving said tread memberor said cut position relatively to each other by said deviation amountupon judging that said deviation amount is in the allowable range, ornot moving same judging that said deviation is in the allowable range;cutting said tread material at said cut position relatively moved or notmoved; and winding said tread material cut out and joining leading andtrailing edges thereof.
 3. A re-treading method according to claim 1 or2 wherein said tread pattern image stored beforehand includes a plannedcut line, and said planned cut line is determined to ensure that all ofdivisional pattern blocks divided by cutting respective blocks of saidtread pattern image have a volume not smaller than a predeterminedvalue.
 4. A re-treading method according to one of claims 1 through 3wherein said cut position is moved relative to said tread material bysaid deviation amount.
 5. A re-treading method according to one ofclaims 1 through 3 wherein said tread material is moved relative to saidcut position by said deviation amount.
 6. A re-treading methodcomprising: detecting a deviation amount between a position at arequired tread length from the leading edge of a vulcanized treadmaterial vulcanized and molded in form of a continuous belt and apredetermined pattern position near said position planned to be cut;cutting said tread material at said predetermined pattern position;winding said tread material cut out on the outer circumference of a basetire while adjusting the length thereof to remove said deviation amountby applying thereto a substantially uniform tensile or compressiveforce; and joining leading and trailing edges of said tread materialwound on said base tire.
 7. A re-treading method according to claim 6further comprising: photographing a tread pattern in a portion distantby the required tread length from the leading edge of said vulcanizedtread material vulcanized and molded in form of a continuous belt; andcomparing the photographed tread pattern image with a tread patternimage stored beforehand to detect said deviation amount.
 8. Are-treading method according to claim 6 or 7, which is a method offeeding said tread material onto said base tire under rotation andwinding said tread material on said base tire, further comprising:calculating the peripheral speed of said base tire along the maximumouter diameter thereof during rotation of said base tire at apredetermined angular velocity; calculating a tread feeding speed whichcan apply a tensile or compressive force to said tread material towardremoving said deviation amount from the peripheral speed of said basetire, said required tread length and said deviation amount; and windingsaid tread member fed at the calculated tread feeding speed.
 9. Are-treading method according to claim 6 or 7, which is a method offeeding said tread material onto said base tire under rotation andwinding said tread material on said base tire, further comprising:feeding said tread material at a constant tread feeding speed;calculating a peripheral speed of said base tire which can apply atensile or compressive force to said tread material toward removing saiddeviation amount from said tread feeding speed, length of said treadmember and said deviation amount; and winding said tread material ontosaid base tire rotated at the calculated peripheral speed.
 10. Are-treading method according to claim 6 wherein said tread material iscut into a tread length which ensures that the ratio of said deviationamount relative to the tread length of said tread material cut out fallsin the range from −4% to 2%.
 11. A re-treading method according to claim6 wherein said tread material is cut into a tread length which ensuresthat the ratio of said deviation amount relative to the tread length ofsaid tread material cut out falls in the range from −2% to 0.5%.
 12. Are-treading apparatus comprising: a transport means for transporting avulcanized tread material vulcanized and molded in form of a continuousbelt; a cutting means for cutting said tread material at a cut position;a photographing means for photographing a tread pattern of said treadmaterial; a storage means for storing a predetermined tread patternimage beforehand; an adjusting means for adjusting the cut position bymoving said tread material and said cut position relative to each other;and a control means including said storage means to control saidtransport means, said cutting means, said photographing means and saidadjusting means, said control means controlling said transport means totransport the vulcanized tread material vulcanized and molded in form ofa continuous belt by a predetermined amount from the cut position;controlling said photographing means to photograph a tread pattern in azone of said tread material including said cut position; comparing thephotographed tread pattern image with the tread pattern image storedbeforehand to detect a deviation amount therebetween; controlling saidadjusting means to relatively move said vulcanized tread material andsaid cut position by said deviation amount; and controlling said cuttingmeans to cut said tread material at the cut position after the relativemovement, thereby to obtain a tread material to be wound on a base tire.13. A re-treading apparatus comprising: a transport means fortransporting a vulcanized tread material vulcanized and molded in formof a continuous belt; a cutting means for cutting said tread material ata cut position; a photographing means for photographing a tread patternof said tread material; a storage means for storing a predeterminedtread pattern image beforehand; an adjusting means for adjusting the cutposition by moving said tread material and said cut position relative toeach other; and a control means including said storage means to controlsaid transport means, said cutting means, said photographing means andsaid adjusting means, said control means controlling said transportmeans to transport the vulcanized tread material vulcanized and moldedin form of a continuous belt by a predetermined amount from the cutposition; controlling said photographing means to photograph a treadpattern in a zone of said tread material including said cut position;comparing the photographed tread pattern image with the tread patternimage stored beforehand to detect a deviation amount therebetween;judging whether the deviation amount falls within an allowable range ornot; controlling said adjusting means when judging said deviation amountis not in the allowable range to relatively move said tread material orsaid cut position by said deviation amount; not moving said treadmaterial or said cut position when judging said deviation amount is inthe allowable range; and controlling said cutting means to cut saidtread material at the cut position relatively moved or not moved,thereby to obtain a tread material to be wound on a base tire.
 14. Are-treading apparatus comprising: a deviation amount detecting means fordetecting a deviation amount between a position at a required treadlength from the leading edge of a vulcanized tread material vulcanizedand molded in form of a continuous belt and a predetermined patternposition near said position planned to be cut; a cutting means forcutting said vulcanized tread material; a base tire support meansrotatably supporting a base tire; a tread material feeding means forfeeding the vulcanized tread material cut at said predetermined patternposition by said cutting means onto said base tire; and a control meansfor controlling the peripheral speed of said base tire or the treadfeeding speed by said tread material feeding means to wind said treadmaterial on the outer circumference of said base tire while adjustingthe length of said tread material by applying a substantially uniformtensile or compressive force to said tread material cut out towardremoving said deviation amount.
 15. A re-treading apparatus according toclaim 14 wherein said deviation amount detecting means includes aphotographing means for photographing a tread pattern in a zone at arequired tread length from the leading edge of said vulcanized treadmaterial vulcanized and molded in form of a continuous belt, and detectssaid deviation amount by comparing the tread pattern image photographedby said photographing means with a tread pattern image storedbeforehand.
 16. A retreading apparatus according to claim 14 or 15wherein said control means correlatively controls the peripheral speedof said base tire and said tread feeding speed from the length of saidtread material and said deviation amount toward removing said deviationamount from said tread material, and winds said vulcanized treadmaterial onto the outer circumference of said tire while applying asubstantially uniform tensile or compressive force to said vulcanizedtread material.